Perforating rule



June 4, 1946. c, Y w 2,401,310

PERFORATING RULE Filed April 9, 1945 IN V EN TOR.

Patented June 4, 1946 UNITED STATES PATENT OFFICE PERFORATIN G RULE Clarence P. Mayhew, Duluth, Minn.

Application April 9, 1945, Serial No. 587,379

1 Claim. 1

This invention relates to an improved die or that which is known by printers and type setters as a perforating rule used for forming roWs of perforations in or through sheets of paper designed to be conveniently removed from an assembly of like sheets, such, for example, as in tablet or pad form commonly used in ofiices, schools, and households where but a sheet at a time is usually removed from the assembly.

Many forms of tickets having a removable portion, or such in their entirety, are thus provided also with rows of perforations or deeply imprinted lines more often adjacent the marginal edge of their holding means.

It probably is superfluous here to mention how often every one has experienced the uneffectiveness of such perforations in their initial functioning, or, in other words, starting the desired ultimate rendition at the proper place, to wit: at the exact terminus of the line of perforations in the very edge of the sheet or portion to be removed.

It so often starts at other than the right place; that in many instances applicant has known of the demand requiring a second operation at the time of assembly of such sheets in forming a V-shaped cut entirel the transverse depth of the side of the assembled sheets at the termini of the perforated line so that, at the least twisting stress on a single, or even plurality of sheets,

the rend will surely start just at the desired point.

Now to avoid the necessity of this second operation and to positively insure against repetition of unsatisfactory experiences as above-related, I have devised the invention disclosed in this application,

In the drawing forming part of the application, like reference numerals indicate like parts, and

Fig. 1 is a side elevation of a common perforating rule as used in the printing art, though much enlarged,

Fig. 2 is a like view of one of the improved rules or dies,

Fig. 3 is an end elevation of Fig. 2, and

Fig. 4 is a still further enlarged fractional end elevation illustrating one method of sharpening the perforating teeth.

The reference numeral I represents the rectangularly-shaped fiat body portion of a die com monly used for making spaced slot-like cuts or perforations, such a die obviously leaving intact at both ends thereof, a narrow strip along both edges of the sheet being perforated and undis turbed which is deemed the principal cause of failure of the severage of the sheet starting at the proper place in line with the perforations; whereas if the extreme outer edge of the sheet were cut or interrupted in the least, any twisting and pulling of the free end of the sheet will have already caused the initial break as evidenced by the double operation supra.

Now in providing a die, the functioning of which will produce optimum conditions for ideal results in removing the sheets, I add the novel features clearly illustrated in Figs. 2, 3, and 4, wherein 2 represents the body portion of the improved die having the usual row of tooth-like cutters 3 which in this instance are shown as having a knife-like cutting edge 4; however said row terminates at both ends in a wider tooth 5 which is sharpened in a like manner to the intermediate smaller teeth simply to insure the extreme edges of the sheet being out.

To further guarantee such positive cutting action as compared with that of the smaller teeth and especially in heavier paper, it may be advisable to have these terminal teeth 5 just a fraction longer than the intermediate ones as shown, and in which event, they may be sharpened on a slightly different plane than that of the smaller teeth, for example, as suggested in Fig. 4 of the drawing,

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

A printers perforating rule having a row of spaced teeth-like perforating elements along one edge thereof, characterized by one of said terminal elements being somewhat wider and slightly longer than the intermediate ones of said teeth to positively insure the terminal perforations occurring through the marginal edge of said sheet.

CLARENCE P. MAYHEW. 

